Pneumatic game

ABSTRACT

A game that uses a source of compressed gas, such as compressed air, to provide gas to move a play object across a play surface. The compressed gas source is capable of providing compressed gas to jets in communication with the play surface for directing the gas to move the play object across the play surface. A triggering device allows the player to select one or more jets and selectively trigger the flow of gas from a selected jet.

FIELD OF THE INVENTION

This invention relates to games. In particular, this invention relatesto a game in which a frame supporting a play surface is equipped to movea play object across the play surface.

BACKGROUND OF THE INVENTION

Many games, such as foosball, air hockey and billiards, involve play ona surface supported by a frame, such as a table. Foosball (or “tablefootball” as it is known in Europe), for example, emulates the game ofsoccer and involves the turning or spinning of players fixed to rods tostrike a ball towards an opponent's goal.

Air hockey involves an air hockey table and players striking a puck witha mallet towards an opponent's goal. Air hockey tables typically havesome mechanism that produces a flow of air from the play surface thatopposes the force of gravity, for the purpose of reducing friction andincreasing play speed.

Billiards is another in this family of games, played on a table with astick used to strike balls, moving them around the table and eventuallyinto pockets.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate by way of example only a preferredembodiment of the invention,

FIG. 1 shows a front perspective view of a game table that uses a linearmagnetic pump as a source of compressed gas;

FIG. 1A shows a plan view of the manual score keeping mechanism of thegame table of FIG. 1;

FIG. 2 shows a front perspective view of a game table that uses an aircompressor as a source of compressed gas;

FIG. 3 shows an elevational view of a blast of gas from a jet directinga play object;

FIG. 4 shows a plan view of the game table of FIG. 2;

FIG. 5 shows a plan view of a game table suitable for use with as manyas four players;

FIGS. 6A to 6C respectively show a front perspective view (from above),a top side view and a side sectional of a jet module;

FIG. 7 shows a schematic view of the connections for a game tableconfigured with a controller and distance measuring sensors, where acompressor is used as a source of compressed gas;

FIG. 8 shows a schematic view of the connections for a game tableconfigured with a controller and distance measuring sensors, where alinear magnetic pump is used as the source of compressed gas;

FIGS. 9 to 12 show schematic diagrams of electrical and pneumaticconnections according to an embodiment of the invention;

FIG. 13 shows a schematic view of the connections between two pneumaticjoysticks, a linear magnetic pump and jet modules;

FIG. 14 shows a schematic view of the connections between two pneumaticjoysticks, a compressor and jet modules;

FIGS. 15A and 15B respectively show a rear isometric view and a rearisometric view (from below) of a pneumatic joystick;

FIGS. 16A to 16D respectively show a bottom side view, rear elevationalview, side elevational view and front elevational view of a pneumaticjoystick;

FIGS. 17A to 17C relatively show a top view, a cross-sectional view anda front elevational view of a ball in the pneumatic joystick of FIGS.16A to 16D;

FIGS. 18A to 18C respectively show a side view, a back view and a topsectional view of pneumatic joystick handle; and

FIGS. 19A to 19E respectively show a top view, a side sectional view, abottom view, a front sectional view, and an isometric view of thejoystick manifold.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to a game which uses triggered directed blasts ofgas, such as air, to move a play object across a play surface.

The preferred embodiment of the invention is accomplished by providing agame comprising: a frame supporting a play surface, for supporting aplay object; a source of compressed gas capable of providing gas formoving the play object across the play surface; a plurality of jets incommunication with the play surface for directing the gas to move theplay object across the play surface, the plurality of jets being coupledto the source of compressed gas by a plurality of conduits; one or moretriggering devices, each for allowing a player to select one or morejets and selectively trigger the release of gas from the one or moreselected jets; and a controller coupled to the triggering devices and aplurality of valves, the plurality of valves being biased towards aclosed position which prevents gas flow through the plurality ofconduits, whereby the controller selects one or more valves based on theone or more selected jets and causes the one or more selected valves toopen in response to the trigger, to allow the gas to move through theone or more selected jets for delivery to the play surface.

A further embodiment of the invention is accomplished by providing agame comprising: a frame supporting a play surface, for supporting aplay object; a source of compressed gas capable of providing gas formoving the play object across the play surface; a plurality of jets incommunication with the play surface for directing the gas to move theplay object across the play surface, the plurality of jets being coupledto the source of compressed gas by a plurality of conduits; and one ormore triggering devices for allowing a player to selectively trigger thegas from at least one jet, the triggering devices coupled to the sourceof compressed gas and to a plurality of conduits coupled to theplurality of jets, whereby the trigger allows the gas to move from thesource of compressed gas through a selected conduit originating at thetriggering device to one or more jets and through the one or more jetsto the play surface, whereby the selected conduit was selected based onthe position of the triggering device.

A further aspect of the invention is accomplished by providing apneumatic joystick comprising: an input for receiving gas; one or moreoutputs for delivering gas; a ball having a conduit one end of which iscoupled to the input and the other end of which is aligned to be incommunication with at least one of the outputs through rotation of theball; a ball-rotating member connected to the ball for rotating theball; a trigger engaging a blocking member within the ball-rotatingmember, the blocking member blocking gas from flowing between the inputand the outputs when the trigger is not depressed, and the triggermoving the blocking member when the trigger is depressed to allow gas toflow between the input and at least one of the outputs.

The game played in the preferred embodiment of the present invention isa game in which players select jets and trigger blasts of air fromselected jets, which are in communication with the play surface, todirect a ball or other play object into a goal or other scoring or pointchanging location in order to score points. The game typically involvestwo people, but other embodiments may involve only one person or morethan two people. A one-player mode allows for play against acomputer-controlled opponent. Two-player mode is one player versusanother player. Three or more player mode allows two or more teams tocompete against each other where one or more teams have more than oneplayer and the control of jets is divided so that one player controlsonly a portion of that team's jets.

As shown in FIGS. 1 and 2, the frame 10, such as a game table, supportsa play surface 20 that is suited to a particular game. The frame 10 maybe whatever shape or size or material necessary to support the playsurface 20. Where the table 10 is designed for soccer, for example, asin the embodiment illustrated, the table 10 may be similar in size andshape to a foosball table. The play surface 20 in the ‘air soccer’embodiment of the invention is substantially flat, and may be green toresemble a soccer field, and includes goals 25 at both ends of the playsurface 20. The play surface 20 may be either smooth or rough intexture, as desired. In other embodiments of the present invention, forexample golf, the playing surface may be provided with “hills” and/orwith obstacles for the players to avoid or overcome.

The game table 10 should provide sufficient stability for rough play,and preferably have areas for a logo or nameplate and for score keeping.The game table 10 may also include a play object return 27 for returningthe play object after a point or goal is scored. The game table 10 mayalso accommodate mechanisms for coin- or credit card-operated use 29 asshown in FIGS. 7 and 8, including a ball release valve 31, for examplefor use in commercial establishments such as restaurants, bars, orarcades.

Referring now to FIG. 3, the play object 30, for example a hollow ball,is light enough to be moveable by a flow of gas, such as air. Suitablematerials include plastic, cork and other lightweight materials. Wherethe game is soccer, the play object 30 is preferably about the size andweight of a ping-pong ball and may be thematically coloured white,yellow, or black and white, or black and yellow in the pattern of asoccer ball.

An enclosing cover 35, which is preferably transparent plastic, may beattached to the table 10 so as to be positioned a sufficient distanceabove the play surface 20 to allow room for the play object 30 to riseabove the play surface 20, and still allow players to view the playsurface 20. The enclosing cover 35 may be flat or curved, and close tothe play surface 20 or farther away, as desired. The enclosing cover 35shields the play surface 20 from air currents proximate the play surface20 which might oppose or affect the bursts of gas from the jets 50, thusproviding more reliable movement and of the play object 30 during play.The enclosing cover 35 also prevents the play object 30 from leaving theplay surface 20 and game table 10 entirely, and protects the playsurface 20 and jets 50 from food and drink spills or other damage.Enclosing cover 35 may include an opening for inserting the play object30 to start or resume play. Alternatively, there may be an opening 28 inthe walls of game table 10 for inserting the play object 30 to or resumeplay.

The source of compressed gas is capable of providing a flow of gas (forexample air) sufficient to move the play object 30 across the playsurface 20 of the game table 10. Gas may be supplied by a compressor 40or an air pump, such as a linear magnetic pump 45, or from a compressedgas canister or any other suitable source of compressed gas, at apressure sufficient to provide the flow of gas necessary to move theplay object 30 across the play surface 20. In a preferred embodiment,the source of compressed gas may be mounted on game table 10, forexample to the underside of the table 10.

In a preferred embodiment, the source of compressed gas contains air ata pressure of 30-60 psi (1-2 scfm), which is suitable for use with 0.25″pneumatic tubing to move a play object 30 that is about the size andweight of a ping-pong ball. Different pressures may be used, varyingwith the cross-sectional area of the jets 50, the size and weight of theball, and the shape and friction of the play surface 20 and the desiredplay object speed.

A plurality of jets 50 are positioned in communication with, preferablyproximate to, the play surface 20, for directing the flow of gas to movethe play object 30 across the play surface 20. The plurality of jets 50is coupled to the source of compressed gas by a plurality of isolatedconduits such as pneumatic tubing 60. In a preferred embodiment, a jet50 has a teardrop-shaped opening, as shown in FIG. 6B, and the jet 50 isat a preferred 10 to 30 degree angle to the plane of the play surfacesurrounding the opening, as shown in FIG. 6C, so the flow of gas out ofthe jet 50 directs the play object 30 in a forward motion as opposed toup and off the play surface 20.

Each jet 50 may be stationary or adjustable. If the jet is stationary,it is preferably integral with the game table 10 and its orientationcannot be adjusted. In the embodiment shown in FIG. 3, the jet 50 isintegral to the game table 10 and there is a channel through the table10 to the jet 50. Preferably, the channel has a tube receiving portion53 and a tube blocking portion 54. The tube receiving portion 53 has acircumference large enough to allow pneumatic tubing 60 to be insertedinto and pushed up the channel until the pneumatic tubing 60 reaches thetube blocking portion 54. The circumference of the tube blocking portion54 is sized to prevent the pneumatic tubing 60 from entering the tubeblocking portion 54 of the channel while allowing gas to flow from thepneumatic tubing 60 through the tube blocking portion 54 of the channelto the jet 50.

If the jet 50 is to be adjustable then the jet 50 may alternatively beincorporated within a jet module 55. A jet module 55, shown in FIGS. 6Ato 6C, can be a removable component that may be affixed to or removedfrom the game table 10 by the player and may be rotated by the playerbefore or even during play. Rotating the jet module 55 changes thedirection of the jet 50 so that gas from the jet 50 will direct the playobject 30 in a different direction when triggered, potentially allowinga player to make passes to other jets or shots off the side or backwalls of the game table 10. A jet module 55 includes a fitting 57 forsecuring the conduit such as pneumatic tubing 60 for delivery of thecompressed gas, such as air, to the jet 50. In the preferred embodiment,each jet module 55 is substantially made of plastic and includes areceptacle such as a hex hole 58 for inserting a tool to rotate themodule in order to adjust the jet direction. A jet module 55 mayalternatively be made of wood, metal or rubber. A portion of theexterior of the jet module 55 forms part of play surface 20.

In a preferred embodiment for the game of soccer as illustrated in FIG.4, there are fifteen jets 50 per team denoted as JOY1JET1 to JOY1JET15and JOY2JET1 to JOY2JET15: five forward jets denoted as JOY1JET11 toJOY1JET15 and JOY2JET11 to JOY2JET15, five middle jets denoted asJOY1JET6 to JOY1JET10 and JOY2JET6 to JOY2JET10 and five back jetsdenoted as JOY1JET1 to JOY1JET5 and JOY2JET1 to JOY2JET5. Each jet 50 isintended to be the counterpart of a player on a team in a real game ofsoccer. Moreover, every jet 50 or a marker proximate to it is preferablycolour-coded or otherwise pattern-coded to identify it as associatedwith the particular player or team who controls it. As shown in FIG. 5,a larger play surface 20 would allow for more jets 50, and similarly,would be more suitable for play by larger groups of people. FIG. 5 showseach of four players controlling fifteen jets 50, respectively denotedas JOY1JET1 to JOY1JET15, JOY2JET1 to JOY2JET15, JOY3JET1 to JOY3JET15,and JOY4JET1 to JOY4JET15. It will be appreciated that the jets 50 canbe provided with different sizes of openings, to provide a burst of gashaving a greater or lesser force than one or more other jets 50. Ifdesired, jets 50 could be positioned at different angles to the plane ofthe play surface in order to cause the play object 30 to movedifferently across and above the play surface 20 when directed bydifferent jets 50. This may be desirable where the play surface 20 hasvaried elevations.

A triggering device such as a joystick 70, having one or more triggers75, is used to allow a player to selectively direct the flow of gas fromthe source of compressed gas to a particular jet 50 in order to attemptto move the play object 30. The joystick 70 is tilted in a directionassociated with the particular jet 50 to be actuated. Preferably jets 50are associated with joystick coordinates in an intuitive manner, suchthat moving the joystick forward corresponds to a player's front-line or“forward” jets and moving the joystick left corresponds to a player'sleft-side jets. When the trigger 75 is depressed, gas, such as air,flows through the jet 50 associated with the direction of the joystick70 at the moment that the trigger 75 is depressed. The joystick 70 maybe electronic or pneumatic and may be composed of one or more of avariety of materials such as plastic, metal and wood. The joystick 70may include leather, plastic or rubber grips, and may be of variouscolours and/or shapes.

Preferably, the joystick 70 is an electronic joystick. When the joystick70 is an electronic joystick, a signal is sent to a controller, such asa microprocessor 80 with an associated input/output processor 82, whenthe trigger 75 is depressed. The microprocessor 80 receives the inputsignal indicating the x-axis and y-axis coordinates of the electronicjoystick handle. At the moment that the trigger 75 is depressed,software code executes to cause one of a plurality of valves 90, whichmay be solenoid valves, to open. Since the electronic joystick 70 iscoordinate-based, it can be configured for use with any number of jets50 by loading conventional software code into the microprocessor 80which is then programmed for use with the appropriate number of jets 50.In a further embodiment, the rotation of jet modules 55 may be driven bya driver, such as a motor, controlled by the microprocessor 80 to allowa player to rotate the jet module 55 before or during play. In thisembodiment, the electronic joystick handle may be twisted in the z-axisto rotate the particular jet module 55 selected by the x-axis and y-axiscoordinates of the electronic joystick handle.

The plurality of solenoid valves 90 may be placed together on manifoldsand each valve 90 is biased to a closed position, blocking the flow ofgas from the source of compressed gas. The source of compressed gassupplies gas, such as air, to the solenoid manifolds 95. The pneumatictubing 60 connects the outlets of the solenoids to the jets 50 incommunication with the play surface 20 by feeding gas from the bottom,beneath the play surface 20. This allows the pneumatic tubing 60 to behidden under the play surface 20. Sample schematics of the connectionsbetween the joysticks 70, controller, manifolds 95, valves 90, source ofcompressed gas and jet modules 55 (seen from the underside of the table10) according to the preferred embodiment are shown in FIGS. 7 and 8.The microprocessor 80 is normally programmed such that a particularvalve 90 is momentarily opened when the trigger 75 is depressed, whichallows a short blast of gas. This helps to conserve the compressed gas.However, the microprocessor 80 may alternatively be programmed such thatthe valve 90 remains open as long as the player is depressing thetrigger 75, in which case the valve 90 will close when the trigger 75 isreleased or the joystick 70 is moved to a different position. Further,other alternatives may be programmed such as multiple blasts in rapidsuccession. The joystick 70 may include additional triggers 75 tofacilitate rapid firing by the player, as the player does not need torelease and re-depress the trigger used to fire the first blast to firea second blast. The microprocessor 80 and solenoid valves 90 are poweredby a power supply 85, which may also be stored beneath the play surface20. Electrical and pneumatic connections for an embodiment of thisconfiguration are shown in FIGS. 9 to 12.

Alternatively, the joystick may be a pneumatic joystick 100 as shown inFIGS. 15A, 15B, and 16A to 16D. When a pneumatic joystick 100 is used,the microprocessor 80, the solenoid manifolds 95 and the plurality ofsolenoid valves 90 are unnecessary. Rather, the pneumatic joystick 100has a base or joystick manifold 105 providing an output tube 140 incommunication with each jet 50 that it triggers. Sample schematics ofthe connections between the pneumatic joysticks 100, source ofcompressed gas and jet modules 55 according to this alternativeembodiment are shown in FIGS. 13 and 14.

As shown in FIGS. 16A to 16D, the pneumatic joystick 100 may comprise ajoystick ball 130 rotated by a member, such as a joystick handle 150,shown in FIGS. 18A to 18C, and adjacent to a manifold 105 feeding outputtubes 140. The joystick ball 130, shown in FIGS. 17A to 17C, comprises agas receiving input 125 and gas delivering output 135. An input tube 120feeds compressed gas from the source of compressed gas to input 125 viaa 90-degree swivel fitting 122. Preferably, the combination of theswivel fitting 122 and the slot cut-out in the joystick housingrestricts the movement of the joystick handle 150 substantially to thex-axis and the y-axis so that the joystick handle 150 and trigger 75 donot rotate around the z-axis during play. Output 135 is an orifice inthe joystick ball 130 in communication with the input 125 via a conduit132, that may be aligned to be in communication with one of theplurality of output tubes 140 on the joystick manifold 105, as shown inFIGS. 19A to 19E, through rotation of the joystick ball 130. When thetrigger 75 is depressed, it moves a blocking member such as springloaded metal rod 110 to allow compressed gas to flow from the flexibleinput tube 120 to one or more of the plurality of output tubes 140.

If a compressor 40 is used as the source of compressed gas, there isconstant compressed gas available at the input 125. If an air pump, suchas a linear magnetic pump 45, is used, an inductive proximity switch 155embedded in the joystick ball 130 or an electrical switch interlockedwith the trigger 75 can send the air pump a which would only allowcompressed air at the input 125 when the trigger 75 is depressed.Optionally, a timer can be added to the switch to limit the flow of airto a momentary blast when the trigger 75 is depressed. This ‘one-shot’feature could alternatively be achieved mechanically in the triggerswitch mechanism in the joystick handle 150. The trigger switchmechanism can be configured to raise the spring loaded metal rod 110 asthe trigger 75 is being depressed, but then drop the rod 110 back downonce the trigger 75 is fully depressed. If a timer or other mechanismfor enabling a one-shot feature is not used, the pneumatic joystick 100allows compressed gas to continue to flow through one or more of theoutput tubes 140 as long as the player is depressing the trigger 75. Ineither case, in this alternative embodiment, little or no compressed gasflows to the jets 50 until the trigger 75 is depressed.

The triggering device need not be an electronic joystick 70 or pneumaticjoystick 100. Alternative triggering devices may include a mouse, atrackball, buttons or a touchpad. Further, in an alternative embodimentthe joystick 100 can itself serve as a trigger when moved to anactuating position, the centre position of the joystick 100 beingneutral and blocking gas from all output tubes 140.

In a further embodiment, a player may compete against acomputer-controlled opponent. In this embodiment, sensors, such asdistance measuring sensors 180, are used to provide inputs to themicroprocessor to determine the coordinates of the play object 30. Themicroprocessor code then activates one or more appropriate jets 50 basedon the location of the play object 30.

The game table 10 may be fitted with either a manual or electronic scorekeeping mechanism. A manual score keeping mechanism 160 may includenumbers or markers that slide to indicate the current score. Anelectronic score keeping mechanism may include a digital display 170 fordisplaying the score or point and sensors 175 to detect when the playobject has entered a score or point changing location. Moreover, aspeaker module 185, as shown in FIGS. 7 and 8, coupled to themicroprocessor 80, programmed with code to control the speaker module185, could be added to announce scoring and to provide sound effectsand, where distance measuring sensors 180 are used, to orally describethe action during play. Such play-by-play commentary might includenaming each jet and announcing any of when a jet passes, shoots, missesshots or passes, scores or prevents a goal. Commentary could also reportgoals and assists after a goal is scored. Furthermore, if desired,“colour commentary” may be mixed in with the play-by-play commentary.

Various embodiments of the present invention having been thus describedin detail by way of example, it will be apparent to those skilled in theart that variations and modifications may be made without departing fromthe invention. This includes, without imitation, variations in theshape, type and size of the frame, variations in the shape, type andsize of the play surface 20, the quantity and specifications of the jets50, the quantity and specifications of blasts of gas after triggering,the quantity and specifications of score or point changing locations,the quantity and specifications of score keeping mechanisms, thequantity and specifications of openings for play object return 27 orplay object entry/re-entry 28, the quantity and specifications of theplay objects 30, the quantity and specifications of the triggeringdevices, including the manner of jet selection, the specification of thecontroller and its programming if used, the quantity and specificationsof the distance measuring sensors 180 if used, the specifications of thecoin or credit card mechanism 29 if used, the specifications of thespeaker module 185 if used, the location and specifications of theenclosing cover 35, the means of supplying a flow of gas and thespecifications of the gas supplied. The invention includes all suchvariations and modifications as fall within the scope of the appendedclaims.

1. A game comprising: a frame supporting a play surface, for supportinga play object; a source of compressed gas capable of providing gas formoving the play object across the play surface; a plurality of jets incommunication with the play surface from underneath the play surface fordirecting the gas to move the play object across the play surface, theplurality of jets being coupled to the source of compressed gas by aplurality of conduits; one or more triggering devices, each for allowinga player to select one or more jets out of a set of at least two jetsassociated with that triggering device and selectively trigger therelease of gas from the one or more selected jets; and a controllercoupled to the triggering devices and a plurality of valves, theplurality of valves being biased towards a closed position whichprevents gas flow through the plurality of conduits, whereby thecontroller selects one or more valves based on the one or more selectedjets and causes the one or more selected valves to open in response tothe trigger, to allow the gas to move through the one or more selectedjets for delivery to the play surface.
 2. The game of claim 1, furthercomprising at least one rotatable jet module comprising at least one ofthe plurality of jets, whereby rotating the jet module changes thedirection of the flow of gas from the jet.
 3. The game of claim 2,further comprising a driver for rotating the rotatable jet module duringplay.
 4. The game of claim 1, further comprising an enclosing cover. 5.The game of claim 1, further comprising a coin or credit card mechanism.6. The game of claim 1, wherein the controller includes amicroprocessor.
 7. The game of claim 6, further comprising a pluralityof sensors that provide inputs to the microprocessor, whereby themicroprocessor executes code to selectively trigger the gas from one ormore jets based on the inputs.
 8. The game of claim 7, furthercomprising a speaker module controlled by the microprocessor forannouncing play-by-play commentary.
 9. The game of claim 1, wherein theplay surface includes one or more score or point changing locations. 10.The game of claim 1, wherein the source of compressed gas is a linearmagnetic pump.
 11. The game of claim 1, further comprising a scorekeeping mechanism.
 12. A game comprising: a frame supporting a playsurface, for supporting a play object; a source of compressed gascapable of providing gas for moving the play object across the playsurface; a plurality of jets in communication with the play surface fromunderneath the play surface for directing the gas to move the playobject across the play surface, the plurality of jets being coupled tothe source of compressed gas by a plurality of conduits; and one or moretriggering devices for allowing a player to selectively trigger the gasfrom at least one jet out of a set of at least two jets associated withthat triggering device, the triggering devices coupled to the source ofcompressed gas and to a plurality of conduits coupled to the pluralityof jets, whereby the trigger allows the gas to move from the source ofcompressed gas through a selected conduit originating at the triggeringdevice to one or more jets and through the one or more jets to the playsurface, whereby the selected conduit was selected based on the positionof the triggering device.
 13. The game of claim 12, further comprisingat least one rotatable jet module comprising at least one of theplurality of jets, whereby rotating the jet module changes the directionof the flow of gas from the jet.
 14. The game of claim 12, furthercomprising an enclosing cover.
 15. The game of claim 12, wherein theplay surface includes one or more score or point changing locations. 16.The game of claim 12, wherein the source of compressed gas is a linearmagnetic pump.
 17. A pneumatic joystick comprising: an input forreceiving gas; one or more outputs for delivering gas; a ball having aconduit one end of which is coupled to the input and the other end ofwhich is aligned to be in communication with at least one of the outputsthrough rotation of the ball; a ball-rotating member connected to theball for rotating the ball; and a trigger engaging a blocking memberwithin the ball-rotating member, the blocking member blocking gas fromflowing between the input and the outputs when the trigger is notdepressed, and the trigger moving the blocking member when the triggeris depressed to allow gas to flow between the input and at least one ofthe outputs.
 18. The pneumatic joystick of claim 17, further comprisinga switch that generates a signal for actuating a pump.
 19. The pneumaticjoystick of claim 18, further comprising a timer for limiting theduration of a flow of gas when the trigger is depressed.
 20. Thepneumatic joystick of claim 17, further comprising a mechanism forraising the blocking member as the trigger is being depressed anddropping the blocking member so that it returns to its original positiononce the trigger is fully depressed.